For example, the cold waters in the Baltic Sea in Northern Europe have a unique
collection of well preserved wrecks from times past, and most of them have not been located – yet.
Some examples of Nordic underwater archaeology are the Vasa, the
Kronan, and the East Indiaman Götheborg
excavations. These ships are impressive, but they are only parts of a
maritime cultural landscape. In this cultural landscape we also include old harbours, anchorages,
coastal inns, barrages built of poles, and coastal settlements. On dry land as well as under water.
Thus, underwater or maritime archaeology does not necessarily deal with wrecks, even if that is the
part scuba divers more often deal with.

Documenting a wreck in north Sweden: A clay pot and one of the tape measures
used.

A common cause for a wreck's
decay is the natural degradation. In the Atlantic, and other salt seas, wooden wrecks are
eaten by the ship worm (Lat: teredo navalis). This animal does not live in the brackish
Baltic Sea, because of its low salinity. That makes the Baltic Sea, as well as the North American
Great Lakes, a unique treasure chamber of historic wrecks, often in depths accessible to scuba
divers.

If you are a scuba diver, your help is needed to preserve this
heritage. Then you too may experience the feeling of
floating weightlessly above a wreck, perhaps one that's not previously discovered.